Evaporation, distillation, or the like apparatus



' 06h l929- w. VOGE/LBUSCH 1,733,476

EVAPORATION, DISTILLATION,0B THE LIKE APPARATUS Filed Feb. 17, 1927 v 2Sheets-Sheet l Oct. 29, 1929. w. VOGELBUSCH 1,733,476

EVAPORATION, DISTILLATION, OR THE LIKE APPARATUS Filed Feb. 17. 1927 2Sheets-She et 2 I I ig-- /6 20 E 1 m I a jig/we 1/6 Patented Oct. 29,1929 UNITED STATES PATENT orrlcr.

EVAPORATION, DISTILLATION, on Tim LIKE arram'rn's Application filedFebruary 17, 1927, Serial No. 168,918, and in the Netherlands April 14,1826.

My invention concerns improvements in or relating to evaporation,distillation or the like apparatus.

It is well known that the efliciency of evaporating-de'vices in whichvapourous or gaseous heating agent circulates around tubes or chamberscontaining liquid to be evaporated is subject to detriment due tovarious causes.

The transfer of heat from the heating agent to said liquid is impaired,for example, when materials which form crusts deposit from the liquid onto the walls of the tubes. It is also possible, however, for resistancesto the heat transfer to be formed on the other side of the walls of thetubes, that is on the side in contact with the vapourous or gaseousheating agent. Such may be due to deposits from the heating agent, asfor example, oil deposit which may occur when steam is employed which,exhaustingfrom an engine or engines, is not entirely free from oil.

The obstacles to heat transfer due to such circumstances may, however,be avoided comparatively simply by the employment of devices for theseparation of the oil from the exhaust steam. It is, on the other hand,more difficult to obviate resistances due to condensate which depositsfrom the heating agent on the tubes and due to the separation ofnoncondensable or permanent gases which form a sheath over the saidtubes. Both the condensed vapour and the permanent gases, being oor heatconductors, form obstacles to the lieat transfer and it is therefornecessary to remove the same.

In the case of eva orating devices with heating tubes the con ensatefrom the heating vapour surrounds the separate tubes in the form of alayer thereof which flows downwardly and which increases in thicknesstowards the bottom. Thepermanent gases, principall air, remain where theheating vapour whic had hitherto formed a carrier for the samedisappears, that is also on the heating tubes, and thus hinder theaccess of fresh steam to the tubes. If provision is made for drawingoil? the permanent gases rapidly, then their detrimental actipn may bereduced, but a disproportionately large quantity of heating vapour islost therewith, the. loss of heating vapour amounting to 15% or more. Inbanks of heating tubes which can be comparatively simply freed from airthe heating vaour issubject to'pressure and temperature ossesaccompanied again by corresponding Eeduction in the efliciency of theheating surace.

The presentinvention relates to evaporating, distillation or the likedevices wherein. provision is made not only for a high circuno latio'nvelocity, at the walls in contact with the heating vapour, of the liquidor solution to be evaporated but also for a heating surface which,practically speaking, ofiers no resistance to heat-transfer.

Accordingly the invention residesin such an apparatus comprising one ormore evaporation stages each of which has one or more heating elements,each of which elements on its side comprises in combination one or morecomparatively large-bore, substantially horizontal circulation tubescommunicating with the li uid space of an evaporating chamber,

a ban of mclined smaller-bore tubes oommunicating with the vapour spaceof the said chamber, a header space connecting the two sets of tubes anda jacket, through which flows a heating agent and which consists of twoparts, each enclosing one of the sets of tubes and being incommunication with each other so in the neighbourhood of the said headerspace.

The .part of the jacket enclosing the inclined tubes i" furnished withbafiles which constrain the heating agent to flow in a tortuous mannerbetween the-said tubes, so that, with a suitable velocity of flow of theheating agent, condensed liquid and permanent gases are forced towardsthe other part of the jacket, en closing the horizontal tube or tubes,whence they may be removed.

wo embodiments of the invention are illustrated by way of example in theaccompanying drawings, wherein 1 Flg. 1 is a vertical section of oneform of eva orating device, ig. 2 is a vertical cross section accordinto line 1-1 of Fig. 1, Fig. 3 is a view of the left side of Fig. 1,

gig. 4 shows a further form of execution an Fig. 5 a detail of thisconstruction in a view from below,

Fig. 6 is 'a view similar to Fig. 2 showing a modified form ofconstruction,

Fig. 7 is a cross sectional view of the construction shown in Fig. 6.

In the case of the construction illustrated in Fig. 1 the heatingelement consists of one the lower part of which communicates with thetube 3. The jacket of the heating element is composed of a part 5enclosing the tube 3, a part 6 enclosing the bank of tubes 4 and a cover8 which closes the header 7 The two parts 5 and 6 of the jacket of theheating member communicate with one another only in the neighbourhood ofthe header 7. Deflecting walls or bafiies 9 are arranged in the part 6of the jacket to constrain the heating vapour, which enters through aninlet 10, to follow a tortuous course inside the jacket 6 so that itflows between the tubes 4 in a direction which is always more or lessperpendicular to the longitudinal dir"ction of the said tubes. Theheating vapour, after entering the jacket 6-by the inlet 10, fio-wstherefore, in a zigzag course through the said jacket and asses finallyinto the part 5 of the jacket w ence it emerges through an outlet 11.

The liquid in the chamber 1 fills also the tube 3, the header 7 and thetubes 4 in which it is heated bythe heating agent which circulatesaround said tubes. Due to the heating the liquid in the tubes 4 isforced upwardly, while the cooler liquid in the chamber 1 is caused tomove downwardly, thus maintaining a circulation. I

The point atwhich the tube 3 communicates with the chamber 1 may be sodisposed that there is always a portion of the liquid at rest in saidchamber 1. This is of advantage when solutions are to be evaporatedwhich deposit salts.

By suitably arranging and distributing the bafiies 9 in the jacketportion 6 it is possible to obtain any desired or necessary velocityofthe heating vapour and to maintain the same constant over the entirecourse thereof in spite of the fact that the quantity of vapour maycontinuously decrease. It is also possible, however, to make thevelocity of the heating vapour larger or smaller at will. In flowingthrough the jacket the heating vapour drives before it not only anycondensate present but also the permanent gases, usually air, into thepart 5 thereof whence the said substances, which would otherwise impairthe heat-transfer, may be removed. The condensate flows out through theoutlet 11 and the permanent gases may be drawn off through a separateoutlet 12. It is possible in this manner to ensure that the heatingsurfaces of the tubes 4 remain free from condensate and permanent gasesso that the heat transfer is not hindered.

It is naturally possible to provide a plurality of stages each with ,twoor more heating elements of the type described and to arrange them' onebeside the other or one above the other in any suitable manner, theacket surrounding the large circulation tube 3 of each stage beingcombined, if desired, to form a single jacket common to all stages. Itis, moreover, not only possible to employ such heating elements invarious ways in an evaporating device but also to construct the heatingelement itself in various ways within the scope of the invention. Theoverall height of the device may, for example, be reduced by disposingthe horizontal tube 3, not below the inclined boiler tubes 4, but besidethe same and it is clear that it is not fundamentally important that thetube 3 should be exactly horizontal and it may be somewhat inclined.

The construction according to Fig. 4 differs from that according toFigs. 1-3 in that the liquid circulating through the tubes 3 and 4 andthrough the chamber 1 is compelled to pass also through the pipe-shapeddevice 13 inserted into the chamber 1, the upper end of this pipe beingconnected to the wall of the chamber 1 and the width of this tube beingdimensioned in such a manner that there is an annular space around thispipe in the chamber 1. The liquid coming from the upper end of the tubes4 flows downwards through the interior of the inserted pipe 13 and asthe lower end of this pipe 13 lies at a level lower than the place wherethe tube 3 is branched oft, the liquid is compelled to flow around thelower edge of the pipe 13 and to ascend in the annular space 14 in orderto arrive at the tube 3. In consequence of the sharp curvature of theway of the liquid at the lower end of the pipe 13 and in consequence ofthe small speed of the liquid at this place solid substances .(e. g.salts) contained in the liquid are separated from the liquid anddeposited on the bottom of the chamber 1. From here these saidsubstances may be removed from time to time so that the liquid flowingthrough the heating tubes gets liberated from such substances.

As for this result it is necessary that the I liquid flows through asharp curvature before it arrives at the tube 4 also other meanssecuring the same efiect may be used. For

instance a vertical wall may be arranged in the chamber 1 around thelower edge of which the liquid would flow before it arrives at the tube3. It is also possible to give the chamber 1 itself such a shape that itforms a way for the flowing liquid with a sharp curvature before itsentrance into the tube 3. The sharp curvature of the course of theliquid need not in all cases be directed downwards; this curvature mayalso be directed otherwise.-

Fig. 4 shows further the space 15 for the vapour subdivided by apartition 16 into two chambers 17 and 18 communicating with each otherby means of a tube 19. A mixture of vapour and li uid leaving the upperends of the heating tu es 4 enters the chamber 17 and whilst theparticles of the liquid collect and flow downwards into the chamber 1,whcrefrom the liquid begins again its circulation through the heatingdevice, the vapour escapes upwards in order to be used for heating orother purposes or to be condensed.

In order to prevent the particles of liquid from being carried awaytogether with the vapour through the tube 19, a hollow cylindricalscreen 21 is fixed to the bottom 16 (Fig. 5 shows this screen as seenfrom below), the inner space of this screen being open at both ends.Therefore the vapour may enter the innner space of the screen throughboth open ends and escape into the chamber 18 through the tube 19. Theliquid collecting on the outside of the screen 21 drops down andassembles with the liquid in the chamber 1. The inner space of thescreen 21 may also be open only on'one side or on more than two sides.

Abovethe tube 19 there is arranged a device 20 for destroying the foamproducedby the liquid; this device may be of a well known construction.

From a constructional point of view, it is quite possible to realize theinvention in a somewhat different way, that is, instead of employing asingle tube 3, two or more such tubes may be provided within the jacket5. Fig. 6 is a fragmentary end view showing three tubes 3 located withinthe jacket 5 and Fig. 7 is a cross sectional view showing thearrangement when more than a single tube 3 is used.

What I claim is 1. In an apparatus for evaporation, distillation or thelike, the combination of at least one chamber for the liquid to beevaporated, this chamber having at its lower part a liquid space andabove this spacea vapour-space for the vapour produced of the liquid,with at the first named tube or tubes and with the 7 other ends with thevapour space ofthe said chamber, the firstnamed tube or tubes being of alarger diameter than the second named tubes, and a jacket consisting oftwo parts, one of which encloses the first named tube or tubes and theother part encloses the second named tubes, these two parts of thejacket communicating with-one another only in the neighbourhood of theouter ends of the said tubes, the second named part of the jacket beingprovided with an inlet for a condensable heating agent and the firstnamed part of the jacket being provided with an outlet for thenon-condensable portion of said heating agent, and an outlet forproducts of condensation.

2. In an apparatus for evaporation, distillation or the like, thecombination of at least one chamber for the liquid to be evaporated,this chamber having at its lower part a liquid space and above thisspace a vapour space for the vapour produced of the liquid, with atleast one heating device arranged beside the said chamber, this heatingdevice consisting of one 'or more horizontal tubes branched oil from theliquid space of the said chamber, a bank of inclined tubes communicatingat their outer, lower ends with the first'named tube or tubes and attheir other higher ends with the vapour space of the said chamber,

the first'named tube or tubes'being of a larger diameter than the secondnamed tubes, and a jacket consisting of two parts, one of which enclosesthe first named tube or tubes and the other part encloses the secondnamed tubes, these two parts of the jacket communicating with oneanother only in the neighbourhood of the outer ends of the said tubes,the second named part of the jacket being provided with an inlet for acondensable heating agent and the first named part of the jacket beingprovided with an outlet for the non-condensable portion of said heatingagent, and an outlet for the products of condensation.

In testimony whereof I aflix my signature.

WILHELM VOGELBUSCH.

least one heating device arranged beside the

